There isn't a simple answer to this question. Much of the advice you will get has bias attached. Start your decision making process by building your own models and making general assumptions while looking into the future. Use this Excel model to start.
Great change management starts with a good tracking system. The far more important part of change management is the rigorous review process at least 2X monthly with your PMs that will limit your risk, increase your opportunities, and train your team.
Construction is a cash-intensive business and change orders are often one of the root causes of poor cash flow. A 30-day improvement to change management workflow can generate over $400K in additional cash flow for a $50M contractor.
A 10% improvement in change order pricing for a $50M per year contractor will add $500K to their bottom line. This is not about simply marking up the change more, but rather, including the many costs that are typically missed or undervalued.